Research news

The fly eye is patterned by a morphogenetic wave driven by the Hedgehog signaling protein. In the 22 September
Science Neumann and Nuesslein-Volhard report that neuronal differentiation in zebrafish eyes
is dependent on a similar wave of hedgehog proteins (Science 2000, 289:2137-2139). Previous work on Pax6 already indicated that the mechanism of eye induction is conserved across the animal
kingdom. But variations in eye structure suggested that events downstream of eye induction
must have evolved multiple times. The new results suggest that at least some of the
downstream events may have evolved only once, before vertebrate and invertebrate lineages
diverged.

References

Growth and differentiation in the Drosophila eye coordinated by hedgehog.